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Two heater coils separately take 10 minu...

Two heater coils separately take 10 minutes and 5 minutes to boil a certain amount of water.Find the time taken by both the coils connected in series to boil the same amount of water.

A

7.5 min

B

15 min

C

20 min

D

25 min

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MODERN PUBLICATION-TEXTUAL QUESTIONS-EXERCISE
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  2. On 220 V supply, a heater heats a volume of water in 5 minutes time. O...

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  3. Two heater coils separately take 10 minutes and 5 minutes to boil a ce...

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  4. Five equal resistors, when connected in seires, dissipated 5 W power, ...

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  5. If a wire of resistance 20 Omega is overed with ice and a voltage of 2...

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  6. A wire is cut into 4 pieces, which are put together by sides to obtain...

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  18. kirchoff's first and second laws are respectively based on law of cons...

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